What Is the Software Development Life Cycle? SDLC Explained

Software development life cycle (SDLC) is the term used in the software industry to describe the process of creating a new software product. Software developers use this as a guide to ensure they produce software with the lowest cost and highest possible quality in the shortest time.

The SDLC has seven stages, and developers use six common models for different projects. Read on to explore each stage and model so you can better understand what it entails to become a software developer.

New to software engineering? Start here.

The Software Development Lifecycle Specialisation from the University of Minnesota is designed for beginner software engineers who want a deeper understanding of Agile and Lean software development methodologies. Start learning today with a free 7-day trial of Coursera Plus.

What is the software development life cycle (SDLC)?

The software development life cycle (SDLC) is the process of planning, writing, modifying, and maintaining software. Developers use the methodology as they design and write modern software for computers, cloud deployment, mobile phones, video games, and more. Adhering to the SDLC methodology helps to optimise the outcome.

In IT, the term "life cycle" was first used in the 1950s and 1960s to describe the stages involved in developing a new computer system, but it is now commonly used to refer to all stages in the production of any software [1]. 

Why is the SDLC important?

The SDLC is important because it helps ensure that the right people are involved in the right activities at the right times. Using a structured approach to developing software helps ensure your project's success. Some of the SDLC's benefits are:

• Understanding your requirements and the goal of the software

• Identify risks at an early stage

• Plan how you will deliver your solution in stages, such as building prototypes or writing functional specifications

• Measure your progress relative to your goals and ensure everything is on track

7 stages of the software development life cycle

Each stage in the SDLC has its own set of activities that team members involved in the development project need to perform. While the process timeline will vary from project to project, the SDLC follows the seven stages outlined below.

Stage 1: Plan and brainstorm.

The first step in the software development life cycle is planning. It's when you gather the team to brainstorm, set goals, and identify risks. At this stage, the team will work together to devise a set of business goals, requirements, specifications, and any high-level risks that might hinder the project's success.

Stage 2: Analyse requirements.

Once you've come up with some ideas, it's time to organise them into a cohesive plan and design. This requires a lot of research and planning to ensure that your final product meets your expectations (and those of your customers). The big step is creating a detailed project plan document and work breakdown structure that outlines the requirements.

Stage 3: Design the mockups.

Once you've got your design plans, it's time for wireframing and mockups. This step builds upon the planning stage, building out the tasks you need to do in the work breakdown schedule. You can find plenty of tools available, such as Adobe XD or InVision, that make this process much easier than ever before.

Stage 4: Develop the code.

The development phase is where coding begins. It is one of the most time-consuming phases in the SDLC and often requires extensive programming skills and knowledge of databases. The team will build functionality for the product or service, which includes creating a user interface and building the database so users can store information in your system.

Stage 5: Test the product.

Before releasing the mockups into final production, you'll need to test them to ensure they are free of bugs and errors. At this stage, you should fix issues before moving forward with deployment. You'll also need to manage how the system will integrate into existing systems, software, and processes.

Stage 6: Implement and launch the product.

Once you've completed all testing phases, it's time to deploy your new application for customers to use. After deployment, the launch may involve marketing your new product or service so people know about its existence. If the software is in-house, it may mean implementing the change management process to ensure user training and acceptance.

Stage 7: Set up maintenance and operations.

The final stage of the software development life cycle is maintenance and operations. This is one of the most critical stages because it's when your hard work is tested.

Maintenance involves updating an existing software product to fix bugs and ensure reliability. It can also include adding new features or functionality to a current product. Operations refer to the day-to-day running of a software product or service, such as performing backups and other administrative tasks.

How to become a software developer

Becoming a software developer requires learning the key skills, programming languages, and concepts to build software products. These days, many people are successfully pivoting or switching their careers from education, the service industry, and more to coding and development. They may complete boot camps or earn professional certificates online, such as IBM's Full Stack Cloud Developer.

Take a look at the course and see if it's a good fit for your career goals:

Software development models

You will find six main software development approach models available in the market. Each has its advantages and disadvantages, as listed below:

Waterfall model: The Waterfall model remains one of the most popular process models in software development. Used since the 1970s, it is a sequential design process that moves in a straight line from one phase to the next. Developers use this approach when the requirements for a product are well-defined, and resources are available. However, it can perform inconsistently if requirements change frequently.

Agile model: The Agile software development process aims to deliver high-quality software early, often, and cheaply. Agile methods prioritise working software over comprehensive pre-planning and documentation, which can slow the creative process. It is a modern approach with short phases that works well when software requirements are likely to emerge as the development process begins. The Agile model offers more flexibility than the Waterfall model but is not always suitable for large-scale projects with complex requirements because it lacks initial documentation.

Iterative model: The Iterative model organises the development process into small cycles instead of a strictly linear progression. This allows developers to make changes incrementally and frequently so they learn from mistakes before they become expensive. Developers get user feedback throughout the process with the Iterative model, so it's ideal for large projects with a strong leadership team.

V-shaped model: Also called the Verification and Validation model, the V-shaped model allows for simultaneous development and testing. Like Waterfall, this model follows a linear progression, but you only move on to the next stage once the team finishes the previous one. The V-shaped model focuses on documentation and planning, so it's ideal for large-scale projects with long schedules. However, the rigidity built into the system only allows for infrequent changes.

Big Bang model: Big Bang has less structure than other software development models. With this model, developers start working with little more than understanding the project requirements. They must figure out things as they go along, as they put most of the resources into the software development stage. Big Bang focuses on getting something working quickly. This approach works well with small projects, where one or two developers can work together to determine requirements and solutions as they code. However, it can be expensive and time-consuming for large projects.

Spiral model: The Spiral model combines elements of other models, namely Waterfall and Iterative. Developers work in shorter cycles, and the work within the cycles follows a linear progression. After each iteration, the software gradually gets better. The key advantage of this model is that it helps manage risk very effectively by focusing on small portions of risk at a time and using different approaches based on the risk profile at that stage. This allows developers to make adjustments without compromising the project's outcome. This approach works well in highly complex, large, expensive projects.

New to software development?

If you haven’t started your journey as a software developer, you might ask yourself, “Is software development for me?” Consider the following signs that this career path might be one that you will enjoy.

• You love problem-solving and logical reasoning.

• You feel at home in the world of technology and hardware.

• You enjoy working with computers and programming languages like C++, Java, or Python.

• You dream of creating a software product that can positively impact people worldwide.

As you take your first steps into a software development career, consider potential employers and particular areas of interest. You can specialise in cloud computing or mobile app development or become a generalist who is an expert at applying the SDLC across many types of software.

How to choose a programming language to learn

It may also be helpful to choose your first software language to learn. Languages like C# and Java are still in demand by employers, but many new languages are emerging, too. Before choosing a language, you need to know what you want to code, but simple front-end development languages like JavaScript, HTML, and CSS are good places to start.

Software developer careers and job outlook

Software development is a field where you can be a generalist or specialise in a particular language or software platform. Software developer salaries vary based on their level of expertise and experience. The following list highlights the range of software developer roles and salaries* in India:

• Lead software developer: ₹26,06,500

• Cloud software developer: ₹12,50,116

• Mobile app developer: ₹5,60,000

• Full-stack software developer: ₹7,72,500

• UX software developer: ₹21,49,456

• AI software developer: ₹9,20,011

• Python software developer: ₹5,77,500

• Java software developer: ₹5,500,000

• PHP software developer: ₹2,71,140

*Salaries sourced from Glassdoor July 2024

Learn software development and SDLC from experts.

The software development life cycle (SDLC) consists of seven stages, guiding developers in creating high-quality software efficiently. Six common models, including Waterfall, Agile, and Iterative, provide different approaches to suit various project needs and goals. Understanding SDLC equips you with the knowledge to contribute to and manage software development projects effectively.

In IBM's Full Stack Software Developer Professional Certificate, you can build job-ready skills and create professional projects for your portfolio. The University of Minnesota's Software Development Lifecycle Specialisation explores software engineering development processes using four philosophies (traditional, secure, Agile, and Lean). To solidify your learning, you'll be given case studies to make decisions based on each methodology and describe why you chose that process. No programming experience required—start learning with a free 7-day trial of Coursera Plus.